A multi-field coupling model for the magnetic-thermal-structural analysis in the electromagnetic rail launch

Abstract

The magnetic-thermal-structural performances (MTSP) in an electromagnetic rail launcher have a significant influence on the successful launch capability. However, it is difficult to explore the MTSP directly through the experimental measurement due to the approximately adiabatic processes in the in-bore environment of the launcher, which further limits us to understand the multi-field properties in the electromagnetic launch process. Considering the interaction between the magnetic field and the thermal field, a transient multi-field coupling model is proposed to investigate the MTSP for the electromagnetic launch based on the finite element method in this paper. The model validation is presented through a comparison of the model prediction with the experimental data of the magnetic flux density and the temperature. The MTSP for an electromagnetic railgun are then analyzed in detail with the effect of the pulse power supply parameter and rail sizes. The results show the pulse power supply parameter has a significant effect on the MTSP near the electromagnetic railgun breech and the rail damage can be decreased with a larger rail size. Moreover, we found the rail was most easily to damage at the rail edge position of the inner sidewall, which is consistent with the groove-shaped damage position in the rail after an experimental test. The results of these investigations will help improve the design of an electromagnetic launcher.